Wife of Omar Mateen, Orlando nightclub shooter, talking with FBI

The wife of Orlando nightclub gunman Omar Mateen drove with him to the dance club on at least one occasion before Sunday's mass shooting, a law enforcement official said.

She also accompanied him to a firearms dealer.

He bought a 9 mm semiautomatic pistol and .223-caliber assault rifle from St. Lucie Shooting Center a few days before the attack.

The FBI is investigating whether his wife, Noor Zahi Salman, 27, knew that Mateen planned an attack on a gay nightclub that left 49 people dead and 53 wounded in the worst mass shooting in U.S. history.

On Monday, the FBI reported that Salman was not cooperating, but by Tuesday, that had changed. Little is known about her.

Her father-in-law, Seddique Mateen, would not discuss her, except to say that she's of Palestinian origin.

On Sunday or Monday, she left the Fort Pierce condominium that she, Mateen and their 3-year-old son shared, but Tuesday she returned with a police escort.

Mateen was killed in a gun battle with Orlando police after a three-hour standoff at Pulse, a gay nightclub south of downtown Orlando.

Wife of Omar Mateen, Orlando nightclub shooter, talking with FBI

During the rampage he had called 911 and pledged allegiance to the Islamic State.

Mateen increasingly sought out Islamic State videos and other radical Islamist propaganda in the months leading up to the shooting, investigators have found.

A counterterrorism official said investigators uncovered the material while reviewing Mateen's searches on the Internet. The official described the progress in the investigation under the condition of anonymity.

Other targets?Mateen had visited a number of Disney properties in the Orlando area since April and was spotted early this month in Disney Springs, an outdoor shopping and entertainment complex at Walt Disney World, according to the official.

Another U.S. official said that it was clear that in another visit two or three months ago Mateen was not simply acting as a tourist during a trip to Disney World.

Mateen may have been casing the sites for potential attack.

Mateen, a Muslim who attended a mosque in Fort Pierce, also is believed to have visited other gay-friendly venues as potential targets, an official said.

Kept to himselfMore details about Mateen's life have emerged since Sunday's attack.

At least four regular customers at Pulse nightclub told the Orlando Sentinel that they had seen Mateen there before.

When asked if he was gay, she said, "I don't know. He never personally or physically made any indication while we were together of that."

His father, Seddique Mateen, in St. Lucie on Tuesday told reporters that he does not believe his son was gay.

He suggested that club regulars had seen him at Pulse earlier because he was scouting it out as he planned his attack.

"He was a — just a normal kid. So what he was — on the back of his mind, I don't know," Seddique Mateen said. "Physically, what I was seeing was O.K."

A former classmate who is gay, Paul Rossi, described Mateen as a sixth-grade bully at Southport Middle School in Port St. Lucie.

"He would call me f - - - - t. He would mimic my lisp … He would use the whole limp hand gesture," said Rossi, a graphic designer in Manchester, Conn. "He was literally the reason that I would go home crying some days."

Rossi was one of two former classmates on Tuesday who described Mateen as happy on Sept. 11, 2001, the day two jetliners crashed into the World Trade Center.

On the school bus going home that day, Rossi said, "He was using his hands as little airplanes and pretending like he was crashing into a building."

"'This is what America deserves,'" Rossi recalled Mateen joking.

Mateen has three siblings, two who are therapists and a third who's studying medicine, his father said.

The elder Mateen said he saw no signs that his son had been radicalized and supported the Islamic State, something he described as "the worst kind of group."

He last saw his son on Saturday, he said, during a quick visit from the younger man to say hello.

As for the victims, Seddique Mateen said: "I'm thinking about them always."

St. Lucie County Sheriff Ken Mascara on Tuesday confirmed that Omar Mateen was shifted away from his assignment as a contract security guard at the St. Lucie County Courthouse in 2013 because of "inflammatory comments."

He did not explain, but the FBI earlier confirmed that agents began an investigation in 2013 after Mateen claimed to have terrorist ties but closed the investigation and a subsequent one the following year because of a lack of evidence.